iPod touch wallpaper fail

hey

i am having a wallpaper fail for my ipod touch. i have tried all morning to set it in the wallpaper section of settings. but when i turn my touch off and on again the front wallpaper is still black :/

not sure what is going wrong. i have had a wallpaper before. and i recently wiped my old images to pu ton new wallpapers (that were the right size) and i am not sure what the problem is.

is there a file size limit?

i just change them all to JPG, and it's still not working :/ i checked the DPI and it's 72. i also shrank the files.

problem fixed. i never knew that my touch did not display a wallpaper when docked/connected with my mac :/